There has been provided a conventional digital broadcasting receiving apparatus which, in order to reduce the influence of a Doppler shift caused by movements of a vehicle, includes two antennas having directivities in a frontward direction and two antennas having directivities in a backward direction, and which compares the received powers of the above-mentioned two antennas having directivities in the frontward direction with those of the above-mentioned two antennas having directivities in the backward direction, and receives digital broadcasting waves by using the two antennas having higher received powers and then performs diversity combining on the digital broadcasting waves (for example, refer to patent reference 1).
Furthermore, there has been provided a conventional digital broadcasting receiving apparatus which, in order to improve the capability of receiving a digital broadcasting wave, carries out comparison and judgment by using a CN value (Carrier/Noise) which is the ratio of the career of the digital broadcasting wave and noise, as well as the received power of the digital broadcasting wave (for example, refer to patent reference 2).    [Patent reference 1] JP,2003-283405,A    [Patent reference 2] JP,2006-33056,A
Conventional digital broadcasting receiving apparatuses are constructed as mentioned above, and can simply switch between two groups of antennas having the same directivity, but cannot perform diversity combining of digital broadcasting waves received thereby by selecting some of all the antennas independently. Therefore, a problem is that, in order to provide antenna directivities in forward, backward, leftward and rightward directions, there is a necessity to dispose a total of eight antennas including two antennas in each and every of all the directions, and therefore conventional digital broadcasting receiving apparatuses are restricted by the installing space of the antennas and the outward appearance of the vehicle. A further problem is that because the antennas of a conventional digital broadcasting receiving apparatus exhibit a directivity in a single direction after the digital broadcasting receiving apparatus has performed diversity combining, when the difference between the angle of arrival of the principal wave of a digital broadcasting wave and that of the delayed wave of the digital broadcasting wave which has arrived at the digital broadcasting receiving apparatus after a delay of a guard time interval or more with respect to the above-mentioned principal wave is small, the receiving capability of receiving the digital broadcasting wave cannot be improved.
The present invention is made in order to solve the above-mentioned problems, and it is therefore an object of the present invention to provide a digital receiving apparatus that can provide a combined directivity in one of various directions by carrying out diversity combining with a combination of antennas having directivities in different directions.